Mitutoyo’s objectives are world-renowned for setting the standard of excellence for long working distance microscope optics. They have achieved the best combination of working distance and optical performance by using a new approach—avoiding outdated conventions used by competitors. Making the objectives larger and longer has made the designs easier (95mm parfocalization length). In order to maintain as high an N.A. and contrast as possible, the lenses are all Plano Apochromats. An apochromatic objective lens is chromatic aberration corrected for red, blue, and yellow while a standard achromatic objective lens is only corrected for red and blue. Plano Apochromats are typically very expensive, but high volume production has made it possible to keep the cost down to that of standard Achromat long working distance objectives. Optimized for bright field illumination (incident illumination parallel to optical axis), these lenses are ideal for in-line illumination applications. For an infinity correction system, a secondary (or tube) lens is required. All stated magnifications are based on a tube lens focal length of 200mm. Mounting thread: M26 x 0.706 pitch (36 TPI).